<?php
/** 
* Global Search Engine for Moodle
*
* @package search
* @category core
* @subpackage search_engine
* @author Michael Champanis (mchampan) [cynnical@gmail.com], Valery Fremaux [valery.fremaux@club-internet.fr] > 1.8
* @date 2008/03/31
* @license http://www.gnu.org/copyleft/gpl.html GNU Public License
*
* General function library
*
* This file must not contain any PHP 5, because it is used to test for PHP 5
* itself, and needs to be able to be executed on PHP 4 installations.
*
*/

/**
* Constants
*/
define('SEARCH_INDEX_PATH', "{$CFG->dataroot}/search");
define('SEARCH_DATABASE_TABLE', 'block_search_documents');

// get document types
include "{$CFG->dirroot}/search/searchtypes.php";

/**
* collects all searchable items identities
* @param boolean $namelist if true, only returns list of names of searchable items
* @param boolean $verbose if true, prints a discovering status
* @return an array of names or an array of type descriptors
*/
function search_collect_searchables($namelist=false, $verbose=true){
	global $CFG;
	
	$searchables = array();
	$searchables_names = array();
	
/// get all installed modules
	if ($mods = get_records('modules', '', '', 'name', 'id,name')){

		$searchabletypes = array_values(search_get_document_types());

		foreach($mods as $mod){
			if (in_array($mod->name, $searchabletypes)){
				$mod->location = 'internal';
				$searchables[$mod->name] = $mod;
				$searchables_names[] = $mod->name;
			} else {
				$documentfile = $CFG->dirroot."/mod/{$mod->name}/search_document.php";
				$mod->location = 'mod';
				if (file_exists($documentfile)){
					$searchables[$mod->name] = $mod;
					$searchables_names[] = $mod->name;
				}
			}		
		}	
		if ($verbose) mtrace(count($searchables).' modules to search in / '.count($mods).' modules found.');
	}
	  
/// collects blocks as indexable information may be found in blocks either
	if ($blocks = get_records('block', '', '', 'name', 'id,name')) {
		$blocks_searchables = array();
		// prepend the "block_" prefix to discriminate document type plugins
		foreach($blocks as $block){
			$block->dirname = $block->name;
			$block->name = 'block_'.$block->name;
			if (in_array('SEARCH_TYPE_'.strtoupper($block->name), $searchabletypes)){
				$mod->location = 'internal';
				$blocks_searchables[] = $block;
				$searchables_names[] = $block->name;
			} else {
				$documentfile = $CFG->dirroot."/blocks/{$block->dirname}/search_document.php";
				if (file_exists($documentfile)){
					$mod->location = 'blocks';
					$blocks_searchables[$block->name] = $block;
					$searchables_names[] = $block->name;
				}
			}		
		}	
		if ($verbose) mtrace(count($blocks_searchables).' blocks to search in / '.count($blocks).' blocks found.');
		$searchables = array_merge($searchables, $blocks_searchables);
	}
	  
/// add virtual modules onto the back of the array

	$additional = search_get_additional_modules();
	if (!empty($additional)){
		if ($verbose) mtrace(count($additional).' additional to search in.');
		$searchables = array_merge($searchables, $additional);
	}
	
	if ($namelist)
		return $searchables_names;
	return $searchables;
}

/**
* returns all the document type constants that are known in core implementation
* @param prefix a pattern for recognizing constants
* @return an array of type labels
*/
function search_get_document_types($prefix = 'SEARCH_TYPE_') {
	$ret = array();
	foreach (get_defined_constants() as $key => $value) {
		if (preg_match("/^{$prefix}/", $key)){
			$ret[$key] = $value;
		} 
	} 
	sort($ret);
	return $ret;
}

/**
* additional virtual modules to index
*
* By adding 'moo' to the extras array, an additional document type
* documents/moo_document.php will be indexed - this allows for
* virtual modules to be added to the index, i.e. non-module specific
* information.
*/
function search_get_additional_modules() {
	$extras = array(/* additional keywords go here */);
	if (defined('SEARCH_EXTRAS')){
		$extras = explode(',', SEARCH_EXTRAS);
	}

	$ret = array();
	$temp = new StdClass;
	foreach($extras as $extra) {
		$temp->name = $extra;
		$temp->location = 'internal';
		$ret[$temp->name] = clone($temp);
	} 
	return $ret;
} //search_get_additional_modules

/**
* shortens a url so it can fit on the results page
* @param url the url
* @param length the size limit we want
*/
function search_shorten_url($url, $length=30) {
	return substr($url, 0, $length)."...";
} //search_shorten_url

/**
* a local function for escaping
* @param str the string to escape
* @return the escaped string
*/
function search_escape_string($str) {
	global $CFG;

	switch ($CFG->dbfamily) {
		case 'mysql':
			$s = mysql_real_escape_string($str);
			break;
		case 'postgres':
			$s = pg_escape_string($str);
			break;
		default:
			$s = addslashes($str);
	}
	return $s;
} //search_escape_string

/**
* simple timer function, on first call, records a current microtime stamp, outputs result on 2nd call
* @param cli an output formatting switch
* @return void
*/
function search_stopwatch($cli = false) {
	if (!empty($GLOBALS['search_script_start_time'])) {
		if (!$cli) print '<em>';
		print round(microtime(true) - $GLOBALS['search_script_start_time'], 6).' '.get_string('seconds', 'search');
		if (!$cli) print '</em>';
		unset($GLOBALS['search_script_start_time']);
	} 
	else {
		$GLOBALS['search_script_start_time'] = microtime(true);
	} 
} //search_stopwatch

/**
* print and exit (for debugging)
* @param str a variable to explore
* @return void
*/
function search_pexit($str = "") {
	if (is_array($str) or is_object($str)) {
		print_r($str);
	} else if ($str) {
		print $str."<br/>";
	}
	exit(0);
} //search_pexit

?>
